Case discussion: How would you treat this patient? [26 March]

This week we have an interesting case from Dr Colin Armstrong. An elderly gentleman presented for a skin check, and a very obvious dark lesion on the lower back was noted.

Please review and describe the clinical and dermoscopic image. What is your evaluation, and proposed next step/s?

  Case discussion     Case discussion

Case discussion


Here is the pathology report. What would you do next and why?


The sections show Clark level 4 malignant melanoma of superficial type. There is a nodular invasive component with a Breslow thickness of 1.9mm. Four dermal mitoses are identified per mm2. The epidermis is focally thinned, however, no ulceration is identified. No lymphovascular invasion, perineural infiltration or satellite nodules are identified. No significant tumour infiltrating lymphocytes are seen. There is no evidence of established regression. Clark level 4 malignant melanoma is completely excised with the following margins:
deep – 8mm
3 o’clock – 7mm
9 o’clock – 10mm
12 and 6 o’clock – greater than 10mm.


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16 comments on “Case discussion: How would you treat this patient? [26 March]

  1. stand out PSL with chaotic features, asymmetry, bluewhite for excisional biopsy w 2mm margin and go from there.

  2. I agree with Thuy Au that this is a chaotic PSL, probably present for a long time,that exhibits several signs of malignancy(grey blue structures,peripheral black clods,segmental pseudopods).
    I would excise with 5mm margins,and be prepared to re-excise the scar with ? 10mm margins if it proves to be an invasive thick melanoma.

  3. “the ugly duckling”lesion, asymmetrical, bluish white and black structureless areas, strongly suggestive of Melanoma; excise with 3 mm clinical margins and follow thru.

  4. A raised , assymmetrical black lesion with a recent growth on the low back by a elderly gentelman .
    Blue and white colour may represent a weil
    Therefore an excisional biopsy with 2 mm margin will be reasonable first step

  5. Black atructureless area with peripheral black dots/ clods and grey area with white lines. MM. excise with 5 mm to rule out melanoma

  6. This is a verrucous melanoma, that mimicks seborheic keratosis but has melanoma hiding underneath it. needs narrow margin excision for confirmation. Features of radial segmental pseudopods, blue white veil, assymetry, chaos, black dots distributed chaotic fashion in the lesion.

  7. I would say it has a good chance of being a pigmented BCC , although melanoma is a possibility as well.
    I struggle sometimes to decide in these cases what would be the best/most efficient way to biopsy a lesion like this.
    An excision w 2 mm margins would be best if this is melanoma and the patient wishes SNL biopsies done afterwards – but that is hindsight. Excision with 3-4 mm could be curative if it turns out to be BCC.
    I think I would do a shave of the entire lesion +2 mm margins – as it will tell me what it is and leave all options open (and is a lot easier/quicker then a full excision).

    1. Looking at it again, it looks quite raised indeed – a shave biopsy would interfere with obtaining a reliable Breslow score so not a good idea – better excise w 2 mm margins for sure!
      Next step. Wide excision margins seems sufficient – although histologically the margins is only 7 mm at 3 o`clock – but the guidelines (10-20mm) are referring to clinical margins as far as I`m aware. So no further surgery required.
      A clinical exam of lymph node stages would be indicated. If no clear evidence of metastasis is present, then no further investigation (staging) would be required. With a high mitotic index and Breslow 1.9mm I would advise a 3-4 monthly review for the next year.

  8. Clinically: A standing out, slightly elevated (nodular) dark PSL.
    Dermoscopically: Clearly Chaotic in structure (asymmetry) and colour (>1 colour).
    Clues: blue-white, gray-white, dark clods/dots (10-11’ o clock), radial streaks and subtle pseudopods > suspicious for MM (Imp: nodular MM).

    Next step: 2-3mm margin excisional biopsy and go from there is a reasonable first step. We usually excited when see a most likely MM with strong clues and drive us bigger margin to cure. But we don’t know exact Dx and BT (breslow thickness) yet. Wider margin excision ranges from 5mm – 20mm based on BT. Seb K is also a little possibility here.

    Melanoma wide excision margins (after initial excision biopsy) recommended in the Clinical Practice Guidelines for the Management of Cutaneous Melanoma in Australia and New Zealand.
    Breslow thickness vs Surgical margin
    Melanoma in situ: 5 mm
    Melanoma 4.0 mm: 2 cm

  9. MM wider margin excision guidelines ( John F Thompson, et al. Melanoma : A management guide for GPs. AFP, Volume 41, No.7, July 2012 Pages 470-473).

  10. Nodular melanoma most likely.
    Excision biopsy with 2mm margins.
    Definitive excision should wait for full histopath.
    I would not shave this type of lesion.

  11. Hello All – great comments so far. Is everyone aware of the Blue-Black Rule? See the abstract here:
    With this knowledge, how would you evaluate this lesion?
    Everyone agrees on biopsy (of course!) but there is interesting variation in biopsy technique – shave / excision, and for excision there is variety of margin
    We will post the pathology result ASAP.
    Regards, David

    1. I haven’t heard of the BB rule (skin cancer novice), I gather it means if blue and black are both present it is likely to be melanoma?

  12. Thanks for this great case and discussion. What is everyone’s view re SLNB of this case, as Breslow thickness of 1.9mm.

    1. SLNB has not shown to improve prognosis or survival of patients with melanoma with extensive studies conducted . It is discouraged as per Dr Aimillos Lallas from Italy who is president of the International dermoscopic society